SIS-041 - Which sister would you choose? 25yo slender nympho vs 21yo submissive masochist

It feels a bit half-baked with Yuria-san as the 'normal' sister and Ayane-sama as the masochist. Wouldn't it have been better to have extreme S and M roles? Yuria-san doesn't really give off a 'lewd sister' vibe, so I think it would've been better if she were a sadist ordering her brother around. Ayane-sama's masochist performance is top-tier. The way she hesitates at the door because she wants to bathe with her brother is irresistible! The brother has a bit of a sadistic, bossy vibe. At the end, when they do it inside... it might have felt more realistic if she had said 'Not inside!' to emphasize the sibling dynamic. Also, I think it would've been better if she were forced to say dirty things by her brother rather than saying them herself. Both Yuria-san and Ayane-sama are lovely, so I want to give it 5 stars, but since I really wanted to see a clash between a sadist and a masochist, I'm giving it 4. Also, I wonder why they set Ayane-sama's age to 21. Does anyone know?